1. Field of the Invention
The present invention generally relates to a communication navigation system and method, which execute, at a communication navigation terminal mounted on a movable body such as a vehicle or the like, a navigation operation such as presentation of an optimum route or the like by using map database information (hereunder, it is referred to as map D/B information as occasion demands) provided from a communication center apparatus for providing map information on a communication network. The present invention also relates to the communication center apparatus for providing map information, the communication navigation terminal, a program storage device, and a computer data signal embodiment in a carrier wave.
2. Description of the Related Art
Generally speaking, a navigation apparatus mounted on a vehicle has a function called xe2x80x9croute searchxe2x80x9d or xe2x80x9cpath searchxe2x80x9d and is designed to be capable of searching for an optimum route connecting an origin and a destination, both of which are designated by a user. It is also designed to lead and guide (navigate) the user to the destination by displaying on a map a current position based on a self-contained or built-in positioning measurement or a GPS (Global Positioning System) measurement and the searched optimum route.
With respect to a traditional navigation apparatus, this kind of route search is performed by microprocessor processing in the apparatus on the basis of the map D/B information stored in a map information recording medium (e.g. DVD-ROM) set in the navigation apparatus. More concretely, the route search is executed by using xe2x80x9cinformation for route searchxe2x80x9d, which enables a search for the optimum route based on predetermined mathematical algorithm, such as link information corresponding to a road part between branching points and intersections, node information including coordinates information (absolute position information on latitude and longitude, or on altitude, latitude and longitude) corresponding to the branching points and the intersections of roads or the like among the map D/B information. Generally, in view of its nature of being for route search, this kind of information for route search is constructed by the link information, the node information, and the like, which are about broad areas where roads are mutually connected, for example, such as throughout Honshu or the main island of Japan, throughout Japan, or the like, so that its volume of data becomes enormous, which increases the whole amount of data of the map D/B information.
Moreover, the map D/B information includes data of added information, which is facility guidance information on tourist attractions/facilities, facility numerals, names (characters) of maps/roads, views of waters/railroads, and roads, in each one of many pieces of map information (drawings). These data as well as the above-described information for route search further increase the volume of data of the map D/B information.
By the way, the search for the optimum route requires the newest map D/B information because of changes, new constructions, and the like on roads.
Therefore, there is a need to equip for the traditional navigation apparatus a map information recording medium that stores the map D/B information which is the newest and whose data volume is enormous. At the same time, there is a need of the display processing and the search processing of an optimum route based on the complicating map D/B information. In this case, there is a need to mount a microprocessor unit (MPU), which is capable of high-speed processing, so that the scale of the processing and that of the apparatus come to increase.
On that account, various communication navigation systems are suggested in order to improve such increase of the scale of the processing and that of the apparatus. In these communication navigation systems, the map D/B information is obtained and provided through two-way wireless communication between a communication center apparatus for providing map information on a communication network and a communication navigation terminal mounted on a vehicle (e.g. refer to the examples of Japanese Patent Application Laying Open NO. Hei 7-262493 xe2x80x9ca system for distributing map information for a movable bodyxe2x80x9d and Japanese Patent Application Laying Open NO. Hei 10-96644 xe2x80x9ca system for guiding a moving routexe2x80x9d).
In this type of the communication navigation system, the newest map D/B information can be provided all at once by updating the map D/B information at one communication center apparatus. By this type of the communication navigation system, the newest map D/B information can be provided quickly and cheaply, comparing the traditional navigation apparatus in which the newest map D/B information is provided for an individual navigation apparatus on a vehicle with the information recording medium, such as a DVD-ROM. Therefore, users side becomes able to easily receive the map D/B information including the newest information for route search or the like.
However, the above-described communication navigation system has the following disadvantage (1) to (4):
(1) In the case that radio or wireless transmission is performed from the communication center apparatus for providing map information to the communication navigation terminal, the map D/B information including the information for route search or the like, whose data volume is enormous, is wirelessly transmitted. Especially depending on a range of an origin and a destination of route search request, its data volume increase, because the route search is executed with respect to a plurality of map information (drawings). Therefore, traffic volume in a wireless section increases, and it becomes difficult to access a circuit. On that account, it becomes necessary to transmit repeatedly to access the circuit from the communication navigation terminal, which generates convergence at the communication center apparatus for providing map information, and further this makes it more difficult to access the circuit.
(2) To solve this problem, it is possible to consider installing a plurality of communication center apparatuses for providing map information on the communication network. In that case, however, the cost for administering operations may increase on the side of administrators that provide the map D/B information and the like.
(3) Moreover, if a radio transmission rate is more speeded up to solve the problem, the scales of data processing and those of apparatus of the communication navigation terminal and the communication center apparatus for providing map information will become large, which will cause the cost of each apparatus to increase.
(4) As for a communication navigation terminal mounted on a vehicle, the communication navigation terminal performs route search processing by own microprocessor. As the route search processing has many processing steps, this causes heavy load of processing in the microprocessor. Furthermore, in recent years, the navigation apparatus tends to unification with a television apparatus, an audio apparatus, and the like (i.e. multifunctionalization). The load in the microprocessor is further increased. This makes processing of the microprocessor difficult in the communication navigation terminals.
On the other hand, it is also considered that the route search is performed on the side of the communication center apparatus for providing map information. In this case, however, the necessity to wirelessly transmit arises after generating the map information, which is specially designed to include the searched optimum route in a thick line or the like, so that the volume of data to be wirelessly transmitted will become enormous. In addition, there arises a need to wirelessly transmit information for outputting as voice or sound or for outputting as image route guidance or the like (hereunder, the information is referred to as route guidance information as occasion demands), such as instructions of left turn, right turn, or straight advance and the like at each guidance position such as a turning point, a branching point, an intersection, or the like on the searched optimum route, so that the volume of data to be wirelessly transmitted will become further enormous.
For this problem, there is suggested a communication navigation system for performing distributed processing of the route search on the sides of the communication navigation terminal and the communication center apparatus for providing map information (e.g. refer to Japanese Patent Application Laying Open NO. Hei 10-300500 xe2x80x9capparatus for route searchxe2x80x9d). However, according to this system, each route data which becomes a candidate, their required time length (cost), and the like are transmitted from the side of the communication center apparatus for providing map information, and the route search is performed on the side of the communication navigation terminal on the basis of them, so that all of the processing become complicated and it needs complex transmission and reception of the considerate volume of data, which is a problem.
It is therefore an object of the present invention to provide a communication navigation system and a communication navigation method, which enable presentation of the optimum route at the communication navigation terminal, while restraining increase of the scale of processing or increase of the scale of an apparatus at the communication navigation terminal and decreasing the volume of data transmitted or received between the communication center apparatus and the communication navigation terminal, as well as the communication center apparatus, the communication navigation terminal, a program storage device, and a computer data signal embodiment in a carrier wave, which allow a computer to function as such a communication navigation system.
The above object of the present invention can be achieved by a communication navigation system provided with a communication center apparatus and a communication navigation terminal, which perform two-way communication on a communication network. The communication center apparatus is provided with a map database for storing therein map database information including information for route search, which enables a search for an optimum route from an origin to a destination by predetermined algorithm; a search device for searching for the optimum route with respect to route search request information that indicates the origin and the destination and that is received through the communication network, on the basis of the information for route search by the predetermined algorithm; and a center side communication device for wirelessly transmitting, through the communication network, coordinates information at a plurality of positions arranged on the searched optimum route. The communication navigation terminal is provided with: a terminal side communication device for receiving the coordinates information wirelessly transmitted; and a display processing device for displaying the optimum route on a map on the basis of the received coordinates information and map information for display.
According to the communication navigation system of the present invention, the communication center apparatus is provided with the map database. This map database stores the large-scale map database information including the information for route search such as the above-described node information, like information or the like, which enables a search for an optimum route from an origin to a destination by predetermined mathematical algorithm such as Dijkstra""s algorithm and so on. When communication navigation is performed, the route search request information indicating an origin and a destination is firstly transmitted by a user communication terminal, such as a cellular phone, a mobile, a facsimile, a personal computer or the like, at a user""s home. In addition, the route search request information may be transmitted by the communication navigation terminal which is carried by a user or which is mounted on a user""s movable body. Secondly, the communication center apparatus receives the route search request information through the communication network. Then, at the communication center apparatus, the search device searches for the optimum route with respect to the received route search request information with the predetermined algorithm such as Dijkstra""s algorithm or the like on the basis of the information for route search included in the map database information. Then, the center side communication device wirelessly transmits, through the communication network, the coordinates information at a plurality of positions arranged on the searched optimum route. The meaning of the xe2x80x9cplurality of positions arranged on the optimum routexe2x80x9d may include a plurality of positions which are arranged at predetermined equal or variable (irregular) intervals on the optimum route based on a map scale (i.e. in such a way that the arrangement of the plurality of position matches on the map). Alternatively, it may include a plurality of positions which are arranged at predetermined equal or variable (irregular) intervals independently of a map scale (i.e. on the real ground). Alternatively, it may include a plurality of positions which are arranged on or in the vicinity of a grid of a map according to a map resolution. Moreover, it may include a plurality of positions placed at connecting positions of parts of the optimum route (i.e. at positions at each of which the angle of a linear line changes) in the case of the approximation of the each part of the optimum route with the linear line. Furthermore, it may include a plurality positions arranged on the optimum route according to various other methods or rules. Namely, method of arrangement of the plurality of positions is not restricted. On the other hand, the meaning of the xe2x80x9ccoordinates informationxe2x80x9d is information that allows specification of a location (coordinates) of each position somehow on a map shown with the map information for display, such as coordinates information that indicates an absolute location on each position, coordinates information that indicates a relative location with the absolute location as a standard, coordinates information that is one-dimensional, indicating a distance from the standard position on the optimum route, and so on.
On the side of the communication navigation terminal, the terminal side communication device receives the wirelessly transmitted coordinates information. Then, the display processing device displays the optimum route on the map on the basis of the map information for display and the received coordinates information. Between the coordinates information and road data (e.g. which is constructed by the collection of the node information and link information) in the map information, there is no particular relation or special connection. However, since coordinates such as latitude and longitude are common between maps, positions indicated by the coordinates information can be specified on a road map in the map information. Namely, if the plurality of positions shown by the coordinates information are plotted on the map based on the map information for display, accordingly, these plotted plurality of positions are arranged on the same route as the optimum route searched on the side of the communication center apparatus. In this case, even if the map scale differs on the side of the communication center apparatus and on the side of the communication navigation terminal, the coordinates, for example, latitude and longitude are in common between maps. Therefore, if the plurality of positions are plotted on a map of an arbitrary scale on the side of the communication navigation terminal, they are placed on the same route as the optimum route searched on the basis of the communication center apparatus after all. As a result, if a map on which the plurality of positions are plotted with certain types of marks and the like is displayed on a display screen, the basic desire of presenting the optimum route from the user is satisfied.
In addition, at the communication navigation terminal, it becomes possible to recognize the optimum route as the road data corresponding to the optimum route not only by plotting the plurality of positions on the map, but by specifying or choosing a route which includes the plurality of positions and which heads to the destination from the origin, i.e. by mapping the plurality of positions onto a road. Especially if the mapping is performed, even if the plurality of positions are plotted at positions in some degree off the road because of errors, inaccuracy of the map, and the like, it becomes possible to specify the optimum route constructed by a series of roads. In this manner, the recognition of the optimum route as the road data on the side of the communication navigation terminal can cause easier performance of various data processing such as, for example, provision processing of route guidance information giving instructions of direct advance, right turn, left turn, and the like at an intersection and the like.
Incidentally, the map information for display used in the display processing by the display processing device may be read out from a storing device such as a DVD or the like provided for the communication navigation terminal. Alternatively, it may be transmitted in advance or with the coordinates information at the same time from the communication center apparatus. In this case again, as for the map information for display, it is possible to plan to decrease its data volume to be transmitted and received as long as it is transmitted separately from the information for route search, whose data volume is enormous as described above.
As described above, in the communication navigation system of the present invention, it is not necessary to wirelessly transmit through the communication network the information for route search whose data volume is enormous as described above and the map database information including this information. Moreover, it is not necessary to newly generate the map information in which the searched optimum route is shown in a thick line or the like to wirelessly transmit it through the communication network. In addition, it is possible to perform the transmission and the reception of the coordinates information more easily than those of the above described distribution processing.
Accordingly, it is possible to decrease the volume of data, which are transmitted and received between the communication center apparatus and the communication navigation terminal, as well as presenting the optimum route at the communication navigation terminal while restraining increase of the scale of the processing and that of the apparatus at the communication navigation terminal.
Therefore, it is possible to effectively avoid the situation that the volume of traffic between wireless sections increases and that it becomes difficult to access circuits, so that one or a few communication center apparatuses can deal with the processes of many communication navigation terminals. Consequently, communication navigation companies can hold down the cost of operation administration. Moreover, since it is not necessary to speed up a wireless transmission, the apparatus performance of the communication navigation terminal and that of the communication center apparatus are relatively low, so that it is possible to plan low cost of the whole system. In addition, as for the communication navigation terminal, it is possible to plan low cost, considering that the processing capacity of a processor can be distributed into more functions such as a television function, an audio function, and the like because of reduction of load of processing on a navigation operation including the relevant communication operation or the like.
In one aspect of the communication navigation system of the present invention, the terminal side communication device transmits the route search request information and the center side communication device receives the route search request information.
According to this aspect, the terminal side communication device provided for the communication navigation terminal carried by the user or mounted on the user""s movable body firstly transmits the route search request information and the center side communication device secondly receives this route search request information. Then, the optimum route is searched for on the basis of this, so that it becomes possible to present the optimum route at the communication navigation terminal, while decreasing the volume of data, which are transmitted and received on the communication network, when the user actually starts moving or while moving.
Another aspect of the communication navigation system of the present invention, the communication navigation system may include a user communication terminal, which performs two-way communication on the communication network and which transmits the route search request information.
According to this aspect, the user communication terminal such as a cellular phone, a mobile, a facsimile, a personal computer, or the like installed at the user""s home firstly transmits the route search request information and the center side communication device secondly receives this route search request information. Then, the optimum route is searched for on the basis of this, so that it becomes possible to request the optimum route before the user actually starts moving, and thereafter, it becomes possible to present the optimum route at the communication navigation terminal when the user actually starts moving and while moving.
In another aspect of the communication navigation system of the present invention, the center side communication device further transmits order information that indicates order of the plurality of positions arranged on the optimum route, and the display processing device displays the optimum route on the basis of the order information in addition to the coordinates information.
According to this aspect, on the side of the communication navigation terminal, it becomes easy to specify or choose the same route as the optimum route on the map based on the map information for display using not only the coordinates information at the plurality of positions but the order information indicating arrange order on the optimum route on the plurality of positions. Especially, in the case that complicated roads such as city streets or the like are included in the optimum route, the fact that the arrange order of the plurality of positions are given and known helps the route specification.
In another aspect of the communication navigation system of the present invention, the coordinates information includes latitude and longitude, or latitude, longitude and altitude at the plurality of positions on the optimum route.
According to this aspect, on the side of the communication navigation terminal, the display processing device can specify the plurality of position on the optimum route on a map according to the latitude and longitude, or latitude, longitude and altitude, so that it is possible to improve accuracy of displaying the optimum route on the map.
In another aspect of the communication navigation system of the present invention, the route search request information indicates at least one passing place that exists between the origin and the destination and that is intended to be passed through in addition to the origin and the destination, and the search device searches for the optimum route with respect to the route search request information indicating the origin, the destination and the at least one passing place.
According to this aspect, one or a plurality of passing places in addition to the origin and the destination are transmitted from the user communication terminal and the communication navigation terminal. Then, the search device searches for the optimum route heading to the destination from the origin through the one or the plurality of passing places. Therefore, the communication navigation system of the present invention can fully demonstrates its effect not only when simply going to the destination, but when going to the destination such as a hotel, a home, or the like, after stopping at one or a plurality of tourist spots, restaurants, souvenir stores, and the like.
In another aspect of the communication navigation system of the present invention, the coordinates information includes information that indicates absolute coordinates of at least one of the plurality of positions on the optimum route, and information that indicates relative coordinates of at least another one of the plurality of positions on the optimum route with respect to the absolute coordinates.
According to this aspect, the coordinates information transmitted from the communication center apparatus to the communication navigation terminal includes absolute coordinates information, such as (X, Y) or (X, Y, Z), and relative coordinates information, such as (xcex94x, xcex94y, xcex94z). The relative coordinates information indicates a position or positions on the optimum route with a variation with respect to the absolute coordinate of another position (a standard position) indicated by the absolute coordinates information. When the relative coordinates information on a certain position is created, if the absolute coordinates of a different position closest to this position, such as the closest position located on the side of the origin or located on the side of the destination, is used as a standard, the value of the relative coordinates information, namely, the variation between this position and the position used as the standard, may be small. Moreover, according to this aspect, as the relative coordinates information which is relatively small is used, the processing of specification or choice of the optimum route on the map on the side of the display processing device can be simplified. Therefore, it is possible to decrease the volume of data to be transmitted and received more than transmitting all coordinates information with the absolute coordinates information.
In another aspect of the communication navigation system of the present invention, the number of the plurality of positions is varied with a scale of a map corresponding to map information used for the search for the optimum route at the search device.
According to this aspect, the number of the plurality of positions can be changed depending on the map scale of the map database information used for the search for the optimum route by the search device. More concretely, for example, if the scale is small, more positions are programmed to be thinned out from among the plurality of positions such as an intersection, a branching point, and the like. Alternatively, if the scale is large, fewer positions are programmed to be thinned out or not to be thinned out at all. Consequently, it is possible to avoid the fact that the data volume unnecessarily increases because of the transmission of the coordinates information associated with many positions which do not match well with the scale of the map information for display used by the display processing device on the side of the communication navigation terminal. Alternatively, it is possible to avoid the fact that the optimum route cannot be displayed because of the transmission of the coordinates information associated with small number of positions which do not match well with the scale of the map information for display used by the display processing device.
In another aspect of the communication navigation system of the present invention, the map database information includes map information having a scale equal to that of the map information for display to be used at the display processing device, and the search device searches for the optimum route on the basis of the map information included in the map database information.
According to this aspect, the search device searches for the optimum route on the basis of the map information of the same scale as that of the map information for display used by the display processing device, and then, the center side communication device transmits the coordinates information of a plurality of positions on the searched optimum route, and then, the display processing device of the communication navigation terminal displays the optimum route on a map on the basis of this coordinates information. When the display processing device displays the optimum route on the map on the basis of the coordinates information, as the map information used by the search device of the communication center apparatus is equal to the map information used by the display processing device of the communication navigation terminal in scale, the plurality of positions on the optimum route based upon the coordinates information matches between both map information. Therefore, the number of positions necessary for specifying the optimum route in the process of the search device is identical to that necessary for specifying and displaying the optimum route on the map in the process of the display processing device. Consequently, it is possible to precisely display the optimum route on the side of the communication navigation terminal, while transmitting and receiving data extremely efficiently.
In another aspect of the present invention, the communication navigation system may be constructed such that the center side communication device receives scale information indicating a scale of the map information for display to be used at the display processing device together with the route search request information, and the search device selects map information having a scale equal to that indicated by the received scale information from among a plurality of map information having various scales, and searches for the optimum route on the basis of the selected map information.
According to this aspect, on the side of the communication center apparatus, the search for the optimum route can be surely performed by using the map information having the scale equal to that of the map information used at the display processing device in scale.
In another aspect of the communication navigation system of the present invention, the center side communication device transmits scale information that indicates a scale of map information which is used for the search for the optimum route at the search device.
According to this aspect, the display processing device can specify or choose the optimum route with respect to the map information for display relatively efficiently in accordance with the scale information (e.g. scale flag) of the map information which is used when the search device searches for the optimum route and which is transmitted from the center side communication device. Especially, even if the scale of a display map changes on the side of the communication navigation terminal, the reference of this scale information can cause easy mapping onto a road and plotting onto a map of the plurality of positions based on the coordinates information. Moreover, if it is turned out to be the same scale on the side of the communication navigation terminal before the display processing, it is possible to perform the specification or the choice of the optimum route on the map information for display by the display processing device extremely quickly and easily.
In another aspect of the communication navigation system of the present invention, the route search request information comprises screen information including character information, and is transmitted and received according to a two-way communication method.
According to this aspect, as the route search request information, screen information is transmitted and received according to a two-way communication method (a screen information two-way communication method). The screen information includes character information used in the browser, such as input processing of an origin, a destination or the like. Thus, the request of route search can be surely performed by using the user communication terminal and the communication navigation terminal.
In another aspect of the communication navigation terminal of the present invention, the route search request information includes character information, and is transmitted and received according to a one-way communication method.
According to this aspect, the route search request information including the character information is transmitted and received according to a one-way communication method. The character information is, for example, information used for a facsimile transmission operation or the like. Thus, the route search can be surely requested by using the user communication terminal and the communication navigation terminal independently of operation conditions or the like of the communication center apparatus. Especially, even if it is impossible to communicate in two way on the communication network because of circuit congestion, the route search can be requested, which is useful.
In another aspect of the communication navigation terminal of the present invention, the route search request information includes transmission time information indicating a time point supposed to transmit the coordinates information, the communication center apparatus further comprises a timing device for measuring a time point shown by the transmission time information and the center side communication device transmits the coordinates information at the time point shown by the transmission time information according to the time measurement by the timing device.
According to this aspect, the communication center apparatus transmits the coordinates information defining the optimum route searched by the search device not immediately after completing the search but following the transmission time information added to the optimum route request information. Namely, the timing device measures a time point shown by this transmission time information and the center side communication device transmits the coordinates information at the time point supposed to transmit. Therefore, even when the communication navigation terminal to be mounted on a vehicle or the like is powered off, the route search can be requested in advance by a user terminal apparatus or the like separately and the coordinates information corresponding to the optimum route can be received later when needed such as when starting to drive, while driving, and so on. Then, this makes it possible to display the optimum route when needed, which is extremely useful in practice.
The above-described object of the present invention can be achieved by a communication center apparatus for performing two-way communication on a communication network with a communication navigation terminal provided with: a terminal side communication device for receiving coordinates information wirelessly transmitted; and a display processing device for displaying an optimum route from an origin to a destination on a map on the basis of the received coordinates information and map information for display. The communication center apparatus is provided with: a map database for storing therein map database information including information for route search, which enables a search for the optimum route by predetermined algorithm; a search device for searching for the optimum route with respect to route search request information that indicates the origin and the destination and that is received through the communication network, on the basis of the information for route search by the predetermined algorithm; and a center side communication device for wirelessly transmitting, through the communication network, the coordinates information at a plurality of positions arranged on the searched optimum route.
According to this aspect, as is the case of the above-described communication navigation system of the present invention, it is possible to decrease the volume of data, which are transmitted and received between the communication center apparatus and the communication navigation terminal, as well as presenting the optimum route at the communication navigation terminal while restraining increase of the scale of the processing and that of the apparatus at the communication navigation terminal.
Incidentally, as is the case of the above-described communication navigation system of the present invention, various aspects are available to the communication center apparatus of the present invention.
The above object of the present invention can be achieved by a communication navigation terminal for performing two-way communication on a communication network with a communication center apparatus provided with: a map database for storing therein map database information including information for route search, which enables a search for an optimum route from an origin to a destination by predetermined algorithm; a search device for searching for the optimum route with respect to route search request information that indicates the origin and the destination and that is received through the communication network, on the basis of the information for route search by the predetermined algorithm; and a center side communication device for wirelessly transmitting, through the communication network, coordinates information at a plurality of positions arranged on the searched optimum route. The communication navigation terminal is provided with a terminal side communication device for receiving the coordinates information wirelessly transmitted; and a display processing device for displaying the optimum route on a map on the basis of the received coordinates information and map information for display.
According to the communication navigation terminal of the present invention, as is the case of the above-described communication navigation system of the present invention, it is possible to decrease the volume of data, which are transmitted and received between the communication center apparatus and the communication navigation terminal, as well as presenting the optimum route at the communication navigation terminal while restraining increase of the scale of the processing and that of the apparatus at the communication navigation terminal.
Incidentally, as is the case of the above-described communication navigation system of the present invention, various aspects are available to the communication navigation terminal of the present invention.
The above object of the present invention can be achieved by a communication navigation method executed in a communication navigation system comprising a communication center apparatus and a communication navigation terminal, which perform two-way communication on a communication network. The communication navigation method is provided with: (i) at the communication center apparatus: a search process of searching, by a predetermined algorithm, for an optimum route from a origin to a destination with respect to route search request information that indicates the origin and the destination and that is received through the communication network, on the basis of information for route search which is included in map data base information stored in a map database and which enables a search for the optimum route from the origin to the destination according to the predetermined algorithm; and a center side communication process of wirelessly transmitting, through the communication network, coordinates information at a plurality of positions arranged. On the searched optimum route, and (ii) at the communication navigation terminal: a terminal side communication process of receiving the coordinates information wirelessly transmitted; and a display process of displaying the optimum route on a map on the basis of the received coordinates information and map information for display.
According to the communication navigation method of the present invention, as is the case of the above-described communication navigation system of the present invention, it is possible to decrease the volume of data, which are transmitted and received between the communication center apparatus and the communication navigation terminal, as well as presenting the optimum route at the communication navigation terminal while restraining increase of the scale of the processing and that of the apparatus at the communication navigation terminal.
Incidentally, as is the case of the above-described communication navigation system of the present invention, various aspects are available to the communication navigation method of the present invention.
The above object of the present invention can be achieved by a program storage device readable by a computer for tangibly embodying a program of instructions executable by the computer to perform a communication navigation method at a communication center apparatus in the above-described communication navigation system (including its various aspects), more concretely, at various component devices such as the center side communication device, the search device, the map database, or the like, provided for the communication center apparatus associated with the above-described present invention.
The program storage device on which the computer program is recorded is such as a CD-ROM (Compact Disc-Read Only Memory), a DVD-ROM (DVD Read Only Memory), a hard disk, a floppy disk or the like. The communication center apparatus associated with the present invention can be relatively easily realized as a computer reads and executes the computer program of instructions or as it executes the program after downloading the program through a communication interface or the like. Moreover, this kind of program can be transmitted from another server apparatus with other data such as video information data, audio information data, map data, and so on.
The above object of the present invention can be achieved by a program storage device readable by a computer for tangibly embodying a program of instructions executable by the computer to perform a communication navigation method at a communication navigation terminal in the above-described communication navigation system (including its various aspects), more concretely, at various component devices such as the terminal side communication device, the display processing device, or the like, provided for the communication navigation terminal associated with the above-described present invention.
The program storage device on which the computer program is recorded is such as a CD-ROM (Compact Disc-Read Only Memory), a DVD-ROM (DVD Read Only Memory), a hard disk, a floppy disk or the like. The communication navigation terminal associated with the present invention can be relatively easily realized as a computer reads and executes the program or as it executes the program after downloading the program through a communication interface or the like. Moreover, this kind of program can be transmitted from another server apparatus with other data such as video information data, audio information data, map data, and so on.
The above object of the present invention can be achieved by a computer data signal embodied in a carrier wave and representing a series of instructions which cause a computer to perform a communication navigation method at a communication center apparatus in the above-described communication navigation system (including its various aspects), more concretely, at various component devices such as the center terminal communication device, the search device, the map database, or the like, provided for the communication center apparatus associated with the above-described present invention.
According to this computer data signal embodied in the carrier wave of the present invention, as the computer downloads the program in the computer data signal through a computer network or the like, and executes this program, it is possible to realize the communication center apparatus associated with the present invention. Moreover, this kind of program can be transmitted from another server apparatus with other data such as video information data, audio information data, map data, and so on.
The above object of the present invention can be achieved by a computer data signal embodied in a carrier wave and representing a series of instructions which cause a computer to perform a communication navigation method at a communication navigation terminal in the above-described communication navigation system (including its various aspects), more concretely, at various component devices such as the terminal side communication device, the display processing device, or the like, provided for the communication navigation terminal associated with the above-described present invention.
According to the computer data signal embodied in the carrier wave of the present invention, as the computer downloads the program in the computer data signal through a computer network or the like, and executes this program, it is possible to realize the communication navigation terminal associated with the present invention. Moreover, this kind of program can be transmitted from another server apparatus with other data such as video information data, audio information data, map data, and so on.
The nature, utility, and further features of this invention will be more clearly apparent from the following detailed description with reference to preferred embodiments of the invention when read in conjunction with the accompanying drawings briefly described below.